When replacing knots on brushes. bake sure to make the hole in the handle bigger than the knot diameter is. You want the glue to hold the knot in place, not the handle.
Something I learned the hard way
- Thread starter Bruce Wayne
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Ok, so that raises a question for me. I turned a handle and put a 22.25 mm hole in it. Will that leave enough room for the glue and a 22mm knot? Sanding it larger is not an option. Should I go with a 20? I want to use a 22mm Best Badger Short Loft knot in it.
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- #3
To be honest I am not the best person to answer that question. What I do know is that the hole should be big enough that if you try lifting the brush up by the bristles, the handle should stay put when there is no glue on the knot.
I would think you're going to have a tough time fitting a 22mm. You might get lucky and the knot is on the small-ish side. If you got it from TGN, they allow for a -1 mm +/- 0.5mm for their knots, so your 22m could be from 20.5mm to 21.5. The knot flairs pretty quickly after the plug, so the deeper you set it, the harder I would think it's going to be to fit it.
Regards.
Regards.
I just measured a 22mm boar from TGN and it's at 20mm
A 20mm is at 19
A 30mm badger is at 29mm.
So I think his knots measure a bit smaller than advertised.
In addition, these measurements are at the glue plug. I think I remember sanding down a glue plug to make it a bit smaller.
I think you'll be ok with a 22mm knot.
A 20mm is at 19
A 30mm badger is at 29mm.
So I think his knots measure a bit smaller than advertised.
In addition, these measurements are at the glue plug. I think I remember sanding down a glue plug to make it a bit smaller.
I think you'll be ok with a 22mm knot.
Main determining factor will be the loft you want,with a low loft of say 46mm the hole has to be oversize.
Make a test board to fit knots,easy to do.
Make a test board to fit knots,easy to do.
I have sanded epoxy plug before without a problem just have to be very careful. In fact I always sand a little to rough it up so epoxy has a better grip. I think a 7/8 forstner drill bit is just about perfect for a 22mm knot
I like to use a handle bore diameter half a millimeter or less than the largest diameter I can find on the knot.When the knot is dry it usually flares out larger that the glue plug at the point where the glue stops and the hair starts.I've found that if you wash the knot by itself and then bind the hairs down with an O-ring the diameter of the bulge will compress so you can use a bore opening ever so slightly larger than the glue plug.I like it to be a tight fit, so tight that the knot has to be worked back and forth with some force to get the knot seated. This controls bloom considerably.With a fit this tight you only need to apply glue to the bottom of the plug to hold it in place.No need to apply glue to the inside walls of the handle or the outside of the plug,no risk of the adhesive squeezing out the top of the handle.
This method doesn't work with solid wood handles though. if the wood absorbs any water the wood will swell and split because there is no room for movement
This method doesn't work with solid wood handles though. if the wood absorbs any water the wood will swell and split because there is no room for movement
On wood (which is a poor handle medium anyhow) seal the inside with two coats of CA glue prior to setting the knot.
One of the easiest ways I've found to find which size hole for which size knot is to take a piece of board and simply drill a bunch of holes in various sizes according to what tools you have and mark the corresponding sizes by each hole. Then you just take your knot and see which hole it fits in best.
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- #11
That is what prompted my original post. I made the hole smaller than the knot was & now I am fighting a crack in a plastic handle.
The handle has to be thick at the bore opening,thin ones don't hold up to well.Found that out using wood.By the way what what size and kind of knot were you installing.
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Sorry for the thread hi-jack. There are great answers here I've been looking for, and haven't asked yet. I'm not worried about the handle holding up, it's made of brass. I was worried about whether or not the knot I wanted would fit in it.
